Leakproof carton and method of making same



July 20, 1965 R. E. TAGGART 3, ,4

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5Sheets-Sheet 1 INVENTOR. ROBERT E. TAGGART July 20, 1965 R. E. TAGGART3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5Sheets-Shet 2 (7 ROBERT E. TAGGART July 20, 1965 R. E. TAGGART 3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5Sheets-Sheet 3 me aaee aegze Rafi Ta INVENTOR. ROBERT E. TAGGART fATTORNEYS July 20, 1965 R. E. TAGGART 3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5Sheets-Sheet 4 INVENTOR. ROBERT-1;. TAGGART ATTO A/EYS y 1955 R. E.TAGGART 3,

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5Sheets-Sheet 5 INVENTOR.

ROB ERT E. TAGGART TTORIQEY5 3,195,425 LEAKPRODF CARTON AND NETHOD OFMAKING SAME Robert E. Taggart, Appleton, Wis, assignor to American CanCompany, New York, N.Y., a corporation of New Jersey Filed June 6, 1962,Ser. No. 200,438 9 Claims. (Cl. 93--36.01)

This invention relates to an improved lined carton and method of makingthe same. More specifically, the invention may be used with particularadvantage as a carton for packaging frozen foods which require aleakproof, sealed package.

Frozen foods such as strawberries are customarily packaged in acontainer employing either a separate moistureproof liner, abag orpouch, or else lined with a moistureproof coating applied to the innersurface of the container. In the case of containers employing a separateliner, the liner is usually glued to the blank prior to erection of thecarton and designed to fold with blank. Usually the lined containersrender the container leakproof only to the upper edges thereof, and ifthe carton is turned upside down the liquid which serves as thepackaging medium Will leak out. Further, since the package is nothermetically sealed, the product is subject to desiccation uponprolonged contact with air. The above noted problems not only makehandling more ditficult but also produce a messy, unattractive package.If a separate filled pouch or bag is employed, valuable packing space islost since the bag or pouch does not completely conform to the contoursof the carton.

' It is the purpose of the present invention to eliminate spoilage ofpackaged products by employing lined cartons in which the attached linerconforms completely to the inner surfaces of the carton. In addition theadjacent edges of the folded-over liner are sealed together to form anessentially airtight package. The invention is particularly advantageoussince either locked or sealed cartons can be employed.

It is an object of the present invention to provide a com, pletelymoistureproof carton from an integral blank havinga liner laminatedthereto in selected areas.

Another object of the present invention is to provide an hermeticallysealed carton which inhibits leakage of the packaging medium anddesiccation of the product.

Yet another object of the present invention is to provide a simplified,efficient method, suitable for use with automatic machinery, for formingan essentially airtight, leakproof package.

Still another object of the present invention is to provide a method forforming a carton having a receptacle portion and a cover portion, liningsaid receptacle portion with a deformable, heat sealable film materialwhich has portions extending beyond the "confines of the receptacleportion, filling said carton and sealing said carton to completely Ienclose the product in the film material.

"According to the present invention, a completely leakproof cartonhaving receptacle and cover portions is produced by first setting up ablank either by locking or sealing flaps, then laminating a deformable,heat sealable film material to the inside of the cover portion as wellas extending panels and flaps, lining said receptacle portion bystretching the film material into essentially complete con- A UnitedStates Patent .0

3,195,425 Patented July 20, 1965 tact with the inner surfaces of saidreceptacle portions, filling, closing and sealing adjacent surfaces ofsaid film ma terial, and finally folding down and attaching the cartonflaps and panels to provide a neat appearing, hermetically sealedcarton.

Further details, advantages and objects of the invention will beapparent from the following specification and appended drawings wherein:

FIGURE 1 is a plan view of an integral blank suitably cut and scored toform a carton having a receptacle portion and a cover portion,

FIGURE 1a is an enlarged fragmental view of the portion of the blankenclosed by a broken line in FIGURE 1,

FIGURE 2 is a perspective view of the blank of-FIG- URE 1 set up,

FIGURE 3 is a diagrammatic representation of a preferred method oflaminating a stretchable film material to the set up carton in a femaledie,

FIGURE 4 is a perspective view of the set up carton with the filmlaminated thereto,

FIGURE 5 is a sectional View of the carton in the female die as the filmmaterial is stretched down into the receptacle portion of the carton,

FIGURE 5:: is an enlarged fragmental view of the portion of FIGURE 5enclosed a broken line, including a portion of the blank and die, andshowing the vacuum application channel,

FIGURE 6 is a perspective view of the carton with the cover portionfolded to overlie the receptacle portion,

FIGURE 6:: is a partial section of the carton taken along line err-6a ofFIGURE 6,

FIGURE 7 is an end elevational view of the carton showing pressureapplying means for heat sealing adjacent layers of film materialtogether,

FIGURE 8 is a perspective view of the carton at a further stage ofsealing,

FIGURE 9. is a perspective view of the carton of the completed carton,

FIGURE 10 is a plan view of a modified carton blank according to thepresent invention employing locking means, and

FIGURE 11 is a perspective View of the completed carton.

Referring first to FIGURE 1, the carton is made of a single foldableblank A of flexible material such as paperboard. The blank is divided byscore lines 10-24 into hingedly connected panels and fiaps includingfront cover panel 30, cover panel 31, rear panel 32, bottom panel 33,front panel 34, end cover panels 35, 45, glue flaps 36, 39, 41, 44, endpanels 37, 42, edge flaps 38, 40 and 43. FIGURE la shows in detail holes25 along score line 12 in the area indicated by the broken lines inFIGURE 1. Similar holes are located along the score lines 13, 17 and 21.The function of the holes will be described more fully hereinafter.

The blank has a thermoplastic adhesive preapplied thereon the stippledareas. Any adhesive which can readily be applied and is activated easilyis suitable for use. Particularly suitable are wax based compositionsemploying any of a variety of additives including resins and polymers.

The blank A is formed into a carton by first applying adhesive to theouter surfaces of glue flaps 36, 39, 41 and 44 and infolding them aboutscores 20, 22, 18, and 16 respectively to form an angle of less thanwith the panels 1 J; to which they are connected, i.e. 32 and 34.

and 13, respectively, to positions at right angles with bottom panel 33.End panels 37 and 42 are then infolded about score lines 21 and 17 sothat the inner end. surfaces of the end panels become adhered to theadhesive-bearing surfaces of the glue flaps;

Rear 7 and front panels, 32and 34, are infolded about score lines 12film sheet down into deep cavities in the die can be ma terially aidedin the first instance byprevi-ously'heating theisheet niateri-al'and inthe second instance by heatirig the ,air or gas.

Edge flaps '38, 40 and 43am 1 folded outwardly to lie in a common planewith'cover panels 30,31, 35 and 45 as shown in FIGURE 2;

The set up carbon is then placed in a'female die 59 as shown, in FIGURE.3 and is passed under a heating element 57 to activate the prea'ppliedadhesive: Located" above the path of travel of the die 59 is a series ofrollers 51, 52, 53 and 56. A roll of deformableheat scalable material 50is mounted to unwind with the web pass-;

ing around 'roll 51 and between a pair of nip rollers 52, 53 whichprovide .a positive pulling action on the web to unwind it from the roll50. Afterpassing through the nip rolls the web passes over' a support54whose edge -coacts with cutting edge 55 to sever a sheet 58. from thetraveling web. As the leadinglportion of the die 59 adjacent thefron-tedge flap 40 passes under sup- 7 port 54, the leading edge of the webattaches itself to Depending upon the speed of op er-ation and theamount of heat applied,heating element 57 which activates the adhesivemay also serve to partially heat the film sheet, increasing itsstretchability without tearing. 7

After the depression I of the film sheet intothe V receptacle portion,cover panel 31 is infolded about score line llso that-cover panelsj30,35 and 45 overlie edge flaps 1 40, 38 and 43, respectivelyp as showninFIGURE 6. FIGURE, 6a, which is a partial section of the canton showsedge flap 40 and superposed front cover-=panel 30 ,withradjacent layersof film sheet 5-8 'interposedthere- ,between. The faceto face filmsurfaces are then sealed together by thsa pueauon' of heat Tandpres-sure via heated bars 64 and 65. While upper bar 6 4 can'be a fiatsolid plate, lower bar 65 must bU-Shapedto conthe activatedadhesive-bearing surface offiap 404 The travel :of the die 59 and theweb of film material is regulated by means not shown so that the leadingedgeslof the web :and the flap '40 coincide. As the carton land filmpass under the roller 56 the pressure laminates the .film material '58to the heat activated adhesive bearing'surfaces of the cart-on;v Thefilm is severed'from the remainder of the'we'b by cutting edge 55 whenthe'traih ing edge of, front, cover flap is reached? The carton with thedeformable, heat sealablesheet material attache-dis .shown'in FIGURE 4.

Thermoplastic deformable ,film materials having the desirablepermeability andnd-eformabili-ty characteristics include those wellknown in the art such as: rubber hydrochloride sold commercially underthe trademark Pliofilm; polymers and copolymers of-polyvinylidenechloride such as Cry-O-Vac and Sarang'vinyl and vinyl copolymers orcombinations; and polyester films such" as Mylar. 'A highly preferredmaterial is-Za laminate consisting of a polyethylene terephthalate(Mylar) approximately. .0005" in thickness, laminated-to a polyethylenefilm approximately .0025! in thickness.

FIGURE 5 illustrates the method by which' the deformable, heat sealablefilm is forced down into con-' tact with the surfaces of the receptacleportion. Initially; a pressure sealer 63 is applied to the upper surface01 film sheet 58 on the portions overlying the .a reaof cover panel 31adjacent the receptacle portion and edge flaps 38, and 43, sealing offthe carton receptacle portion bars 64 'and 65 during theface to facesealing of the Ij I As an alternativeto the embodiment descri form tothe configuration of three sides of the carton.

j Endicover' panels 35 and *areithen'folded down against the underlyingend panels 37 and 42, respectively,

.as shown'in FIGURE 8. Thei rclosure is completed by forming triangularfolds in the unsupported projecting portions of film sheet 58 whilefolding front cover panel 1 30 downwardly about score 10/:0 lie againstfront panel a 34. The cover panels 30, 35.and 45 are readily sealed tothe underlying front and end panels 34, 37 and 42,

respectively, by 'm-eans. of the interposed heat scalable.

film material. Having been heated substantially by t-he film, the filmreadily seals to the carton surfacewith the use of heat and pressure.The completed carton is shown inFIGURE 9. If desiredfan adhesive maybeemployed to implement the bonding-of panels 30, '35 and 45 to theyrespective underlying. panels in case the heat sealing properties 'ofthe tfilmrnaterial. to the paperboard should prove 'insufiicient to'produce the. required bond. V r 7 'bed above, the-lined carton maybefo'rmedi'from a blank employing locking means forcrection and closing.The modimaintained in the cavity of" the female die 59.3 A vacu-2 um isthen drawn thnou gh connectingchannelsfit), adf

jacent the bottom-edges of the, receptacle portion, and.

through channel 61 leading to. the vacuum'source The nels :-and'thehole. 25 through which't-he vacuum; is

. a a '1 Y Alternatively, the film can be forced downinto the die drawn.

. companying description.

V ffiedlblank" B as showninrFIGUR'E, 10 is divided by score lines -116and cut lines 117 into hingedly con.

nected' panels and flaps including front cover panel 120,

cover panel 121, rear panel 12 2,bot-tom' panel 123, front "panel- 124,end coverpanels 125, 133, locking flaps 126, 129 ,ef1d p-anels.127,13:1, edge flaps 128, 130 and 132, and locking tab 134. Cut lines definefemale locking slits 138, 139, 140 and 142 whichreceivemale locking tabs137, 141, 136 and-135,respectively, as shown in FIGURES 'loxland l1; v

'. TheblankB is formed into a carton by engaging locking tabs 13 7 inslits 138 and locking'tabs 141 in slits 139. The, set up carto'n issimilar in appearance at'this stage to the first embodiment shown inFIGURE 2. After erection, thefcarton is'lined and the; film'materialsealed by the method set fonth in-FIGURES 3-7 and the ac-. The closureof the carton is.

completed 'by folding the cover'panels 120, 125 and 133 downwardlyabout/score lines 100,- 105 and 114 respectively. Male locking tabs, and.136Tare inserted in female locking slits 142. and 140, respectively, topro- 'duce the completed closedcarton shown in FIGURE cavity by air orgaspressure. In this'method, the edges of the film sheet '58 adjacentthe receptacle portion are again sealed offby pressure topreventleakage. A press ing form 62 then descends on pressure sealer 63 form-,

Air or' gas under pressure is.

ing another airtight seal.

then forced down through the centralshaft of the press- 11.{ Theadhesive, indicated by the :stippled'are'a in'FIG- UR E- 10, ispurposely omitted from locking tabs 134,

135, l3 6=to prevent undesirable adhesion of the; liner to the surfacesof. these components of the carton. I It as obvious, of course, that theparticular configuration of the locking means can be changed as desired.

carton having. side and bottom panels'and edge fiapsf If desired, thecoverpanel may be. omitted and" a hingedly connected to the upper'edge'sof the sidepaliels ing form 62 depressing thefilm sheet .58 until it conforms tothe configuration of the receptacle portion.

In the methods described abov-e the stretching of -the may be employed.,The sheet material'ia'then, adhered to.-a.ll;edge;fiaps -andsubsequently depressed intothe 75 receptaclei'portionfin themannerpreviously described.

To close the car-ton after filling, the extended free end of the film isfolded over to cover the receptacle and the edge fiaps and adhered tothe underlying film in the edge flap areas. The edge flaps are thenfolded down and sealed to the outside carton side panels as previouslydescribed. A significant saving in sheet material may be realized by aslight modification in the above procedure, in which the edge flap fromwhich the free end of the sheet material extends is folded inwardly topartially coverthe contents of the carton and the extended film thensealed to the remaining edge flaps in the regular manner. These flapsare then folded out and down to be sealed to the carton side panels aspreviously described.

The present invention provides a lined carton using a single blank and asingle liner. The carton can readily be set up, lined, filled with thecommodity to be packaged, and closed by automatic machinery. Thecontents are encompassed by an essentially airtight, leakproof,hermetically sealed construction which insures freshness and retardsspoilage. Both the size and configuration of the adhesive patterns usedto heat seal the deformable, heat scalable film material to the cartonblank can be varied as desired.

It is understood that the description of the carton construction givenherein is merely illustrative of the essential features of theinvention, and is not limited to the specific dimensions or contours,which may be greatly varied or modified and which variations areintended to be included within the scope of the appended claims.

I claim:

1. A method of forming from an integral carton blank an essentiallyhermetically sealed carton having a perforated bottom panel, hingedlyconnected side panels, and edge flaps hingedly attached to the upperedges of said side panels, which method comprises applying an adhesiveto said edge flaps; setting up said blank to form a carton having theadhesive bearing surfaces of said edge flaps facing upwardly; attachinga deformable, heat sealable sheet material to the adhesive bearingsurfaces of said edge flaps with said sheet material extending outwardlyan appreciable distance from one side of the carton; depressing saidsheet material into said carton to conform to the configuration thereof;folding over said extended sheet material and sealing the edges to theunderlying portions of said sheet material which are adhered to saidedge flaps.

2. A method of forming from an integral carton blank an essentiallyhermetically sealed carton having a bottom panel defined by perforatedscore lines, hingedly connected side panels, and edge flaps hingedlyattached to the upper edges of said side panels, which method comprisesapplying an adhesive to one surface of each of the edge flaps; settingup said blank to form a carton having said edge flaps extendingoutwardly in a common plane and their adhesive bearing surfaces facingupwardly; adhering a deformable, heat scalable sheet material to theadhesive bearing surfaces of said edge flaps with said sheet materialextending outwardly an appreciable distance from one side of the cartonand being at least twice the size of the area defined by the outer edgesof said edge flaps; applying pressure means to hold said sheet materialin airtight contact, with the upper edge of said carton; depressing saidsheet material into said carton to permanently conform to theconfiguration thereof; folding over said extended sheet material andsealing the edges to the underlying portions which are adhered to saidedge flaps.

3. The method of claim 2 wherein said sheet material is depressed by gasunder pressure directed down on top of said sheet forcing the air undersaid sheet outwardly through the perforations in said score lines.

4. The method of claim 2 wherein said sheet is depressed by a vacuumdrawn through the surfaces in the score lines defining the bottom panelof the carton.

5. The method of claim 1 wherein said sheet material is depressed by gasunder pressure directed down on top of said sheet material forcing theair under said sheet material outwardly through the perforations in thebottom panel.

6. The method of claim 1 wherein said sheet material is depressed by avacuum drawn through the perforations in the bottom panel.

7. A method of forming from an integral carton blank an essentiallyhermetically sealed carton having a bottom panel defined by perforatedscore lines, hingedly connected side panels, and edge flaps hingedlyattached to the upper edges of said side elements, which methodcomprises applying an activatable adhesive to one surface of each ofsaid edge flaps; setting up said blank to form a carton having said edgeflaps extending outwardly in a common plane and having their-adhesivebearing surfaces facing upwardly; passing said carton through means toactivate the preapplied adhesive; adhering a deformable, heat-scalablesheet material to the upper adhesive bearing surfaces of said edge flapswith said sheet material extending outwardly an appreciable distancefrom one side of the carton and being at least twice the size of thearea defined by the outer edges of said edge flaps; applying pressuremeans to hold said sheet material in airtight contact with the upperedges of said carton; de' pressing said sheet material by means of aVacuum drawn through the perforations in said score lines into saidcarton to permanently conform to the con-figuration thereof; foldingover said extended sheet material; sealing the edges to the underlyingportions adhered to said edge flaps; and folding down said edge flapsinto engagement with said side panels and sealing them together by saidheat-scalable material.

8. A method of forming from an integral carton blank an essentiallyhermetically sealed carton having a bottom panel defined by perforatedscore lines, hingedly connected side panels, and edge flap-s hingedlyattached to the upper edges of said panels, which method comprisesapplying an adhesive to one surface of each of said edge flaps; settingup said blank to form a carton having the adhesive bearing surfaces ofsaid edge flaps facing upwardly; attaching a deformable, heat-scalablesheet ma terial to the adhesive bearing surface of said edge flaps withsaid sheet material extending outwardly an appreciable distance from oneside of the carton; depressing said sheet material into said carton toconform to the configuration thereof by directing gas under pressuredownwardly on top of said sheet material forcing the air under saidsheet material outwardly through the perfo rations in said score lines;and folding over said extended sheet material and sealing the edges tothe underlying portions of said sheet material which are adhered to saidedge flaps.

9. A method of forming from an integral carton blank an essentiallyhermetically sealed carton having a bottom panel define-d by perforatedscore lines, hingedly connected side panels, and edge flaps hingedlyattached to the upper edges of said panels, which method comprises appling an adhesive to one surface of each of said edge flaps; setting upsaid blank to form a carton having the adhesive bearing surfaces of saidedge flaps facing upwardly; attaching a deformable, heat-scalable sheetmaterial to the adhesive bearing surface of said edge flaps with saidsheet material extending outwardly an appreciable distance from one sideof the carton; depressing said sheet material into said carton toconform to the configuration thereof by drawing a vacuum through theperforations in the score lines defining the bottom panel of the carton;and folding over said extended sheet material and sealing the edges tothe underlying portions of said sheet material which are adhered to saidedge flaps.

(References on following page)

1. A METHOD OF FORMING FROM AN INTEGRAL CARTON BLANK AN ESSENTIALLYHERMETICALLY SEALED CARTON HAVING A PERFORATED BOTTOM PANEL, HINGEDLYCONNECTED SIDE PANELS, AND EDGE FLAPS HINGEDLY ATTACHED TO THE UPPEREDGES OF SAID SIDE PANELS, WHICH METHOD COMPRISES APPLYING AN ADHESIVETO SAID EDGE FLAPS; SETTING UP SAID BLANK TO FORM A CARTON HAVING THEADHESIVE BEARING SURFACES OF SAID EDGE FLAPS FACING UPWARDLY; ATTACHINGA DEFORMABLE, HEAT SEALABLE SHEET MATERIAL TO THE ADHESIVE BEARINGSURFACES OF SAID EDGE FLAPS WITH SAID SHEET MATERIAL EXTENDING OUTWARDLYAN APPERCIABLE DISTANCE FROM ONE SIDE OF THE CARTON; DEPRESSING SAIDSHEET MATERIAL INTO SAID CARTON TO CONFORM TO THE CONFIGURATION THEREOF;FOLDING OVER SAID EXTENDED SHEET MATERIAL AND SEALING THE EDGES TO THEUNDERLYING PORTIONS OF SAID SHEET MATERIAL WHICH ARE ADHERED TO SAIDEDGE FLAPS.